Torque converters are familiar in drive trains of motor vehicles and are preferably disposed between an internal combustion engine and a transmission. Thereby, the converter's function with excessive torque increase is preferably utilized for starting the motor vehicle, in that the torque from the housing that is driven by the internal combustion engine is transmitted via the impeller that in turn drives the turbine that transmits torque via an output part with the support on a stator for torque increase to a transmission input shaft of the transmission unit. At higher speeds, the lock-up clutch is closed so that torque is transmitted directly from the housing via the output part to the transmission input shaft, bypassing the converter components, and the deteriorating efficiency of converter components at higher speeds is inhibited.
The internal combustion engines finding application, particularly 4-cylinder diesel engines, feature high rotational irregularities so that torsional vibration dampers are provided in the housing of the torque converter, which can be disposed effectively in the closed lock-up clutch between the housing and the output part and/or for an open lock-up clutch, between turbine and the output part of the torque converter. Thereby, a torsional vibration damper in the known manner is understood as an arrangement with an input- and an output part, which, for instance, contrary to the effect of energy accumulators disposed over the circumference, are limitedly rotatable relative to one another. Such torsional vibration dampers can contain several damper stages that are disposed in series and/or in parallel to one another.
For improved vibration insulation of torsional vibrations of the internal combustion engine, the application of centrifugal force pendulums in the housing of the torque converter has been disclosed, which can also be integrated effectively in the housing in connection with torsional vibration dampers. Such an arrangement of damping units may not be adequate in internal combustion engines of the above-mentioned type, so that pendulum weights on the centrifugal force pendulum are possible. The design of the centrifugal force pendulum can therefore be difficult, particularly at low speeds with high swivel angles of the internal combustion engine. Limit stops of pendulum weights or masses act, particularly, on the drive train of a motor vehicle, through a humming sound that causes discomfort.